Which Screening Tools Can Predict Injury to the Lower Extremities in Team Sports?

Testing in Intermittent Sports-Importance for Training and Performance Optimization in Adult Athletes

ABSTRACT

Performance in intermittent sports relies on the interplay between multiple physiological systems determining the capacity to perform short explosive efforts as well as repeated intense actions with limited recovery over the course of an entire game. Testing should reflect these demands to allow for sport- and position-specific capacity analyses that eventually may translate into optimized training and improved performance. This may include individual load management and optimized training prescription, intensity targeting for specific positions or individual athletes, as well as benchmarking for monitoring of training progression and enhanced engagement of athletes. This review provides an overview of available tests in different exercise domains identified as relevant (from assessment of single explosive actions to intermittent endurance capacity), forming the basis for recommendations on how to compose a comprehensive yet feasible test battery that may be integrated into the seasonal competition and training plan. The test procedures should cover the performance spectrum of relevance for the individual athlete-also in team sports to account for positional differences. We emphasize the benefits of sport-specific tests, highlight parameters of importance for test standardization, and discuss how the applied test battery may be supplemented with secondary tests directed toward specific energy systems to allow for more in-depth analyses when required (e.g., in terms of an underperforming athlete). The synergy between testing and tracking of match performance (utilizing time-motion or global positioning systems) is highlighted, and although tracking cannot substitute for testing, combining the tools may provide a comprehensive overview of the physiological demands and performance during competition contextualized to the athletes' maximal exercise capacity.

The effects of functional training on physical fitness and skill-related performance among basketball players: a systematic review

Background: Evidence suggests that functional training (FT) positively impacts physical fitness and sports performance. However, a systematic review addressing the effects of FT on basketball players remains absent. This systematic review aims to explore the influence of FT on physical fitness and skill-related performance in basketball players. Methods: We searched six databases: Web of Science, Scopus, PubMed, China National Knowledge Infrastructure (CNKI), EBSCOhost, and Google Scholar. The search utilized a combination of keywords related to FT, physical fitness, and basketball. The Eligibility Criteria of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA 2020) guidelines were followed in this systematic review. Results: 11 studies were ultimately included in this review, collectively recruiting 333 basketball players. These studies demonstrated that FT significantly improved muscle strength, linear speed, cardiovascular endurance, flexibility, balance, and muscular endurance. However, the effects of FT on power, change-of-direction speed, and basketball-related performance were inconsistent. Most studies showed FT significantly improves these three variables, but a small number of studies did not find positive effects of FT using specific tests including standing long jump, Sargent jump, touch high, lane agility, lateral shuffle, dribbling line drill, and free-throw tests. Conclusion: FT is an effective training method for enhancing physical fitness including muscle strength, linear speed, cardiovascular endurance, flexibility, balance, and muscular endurance. However, the effects of FT on power, change-of-direction speed, and basketball-related performance were divergent. Some tests were not improved after FT potentially due to the short program lengths and training session durations, varied athletic levels of players examined, and different foci of the FT exercises administered. The collective evidence suggests FT programs, especially the specific exercises prescribed, should be tailored to the desired training objectives. More studies investigating the effects of FT on physical fitness and basketball-related performance with established tests are encouraged in the future to expand the current evidence base. Systematic Review Registration: https://inplasy.com/, Identifier INPLASY202360072.

Lower Limb Proprioception in Low Back Pain and Its Relationship With Voluntary Postural Control

This study aimed to investigate whether patients with low back pain (LBP) had impaired lower limb proprioception and its association with somatosensory acuity. Thirty patients with LBP and 30 asymptomatic people volunteered, using Sway Discrimination Apparatus tests to assess somatosensory acuity during voluntary anteroposterior and mediolateral postural sway. Results showed significantly reduced somatosensory acuity in mediolateral sway in LBP patients (p = 0.005) with ankle, knee, and hip proprioception showing significantly impairment compared to asymptomatic controls (all p ≤ 0.012). Regression analysis showed that ankle and hip proprioception were significantly associated with somatosensory perception (0.001 ≤ p ≤ 0.026, 0.067 ≤ R2≤ 0.235). Overall, findings suggested a global deterioration of lower limb proprioception in LBP patients, with ankle and hip proprioception playing crucial role in somatosensory perception.

A Case Report of a National Judo Champion: Is Return to High-Level Contact Sports Possible After Meniscus Allograft Transplantation?

Meniscus allograft transplantation (MAT) is a surgical procedure reserved for (relatively) younger individuals who remain symptomatic after the resection of a voluminous part of the meniscus. Return to sports and certainly the level of sport post-MAT are highly variable. We present a unique case of a national judo champion who was able to compete at the highest level following MAT. Considerations regarding the rehabilitation and follow-up of this patient are provided, and the risk of rerupture is discussed. Although returning to high-level contact sports post-MAT is possible, the risk of rerupture should be considered.

Test-retest, intra- and inter-rater reliability of the reactive balance test in patients with chronic ankle instability

Introduction

The Reactive Balance Test (RBT) could be a valuable addition to research on chronic ankle instability (CAI) and clinical practice, but before it can be used in clinical practice it needs to be reliable. It has already been proven reliable in healthy recreational athletes, but not yet in patients with CAI who have shown persistent deficits in dynamic balance. The study aimed to determine the test-retest, intra-, and inter-rater reliability of the RBT in patients with CAI, and the test-retest and inter-rater reliability of the newly developed RBT score sheet.

Methods

We used a repeated-measures, single-group design to administer the RBT to CAI patients on three occasions, scored by multiple raters. We included 27 participants with CAI. The study used multiple reliability measures, including Pearson r, intra-class correlations (ICC), standard error of measurement (SEM), standard error of prediction (SEP), minimal detectable change (MDC), and Bland-Altman plots, to evaluate the reliability of the RBT's outcome measures (visuomotor response time and accuracy). It also assessed the test-retest and inter-rater reliability of the RBT score sheet using the same measures.

Results

The ICC measures for test-retest reliability were similar for accuracy (0.609) and VMRT (0.594). Intra-rater reliability had high correlations and ICCs for accuracy (r = 0.816, ICC = 0.815) and VMRT (r = 0.802, ICC = 0.800). Inter-rater reliability had a higher ICC for VMRT (0.868) than for accuracy (0.690).

Conclusion

Test-retest reliability was moderate, intra-rater reliability was good, and inter-rater reliability showed moderate reliability for accuracy and good reliability for VMRT. Additionally, the RBT shows robust SEM and mean difference measures. The score sheet method also demonstrated moderate test-retest reliability, while inter-rater reliability was good to excellent. This suggests that the RBT can be a valuable tool in assessing and monitoring balance in patients with CAI.

Neuromuscular Response during Different Side-Cutting Maneuvers and Its Influence on the Risk of Knee Injuries

BACKGROUND

The objective of this study was to investigate the impact of a customized exercise program on electromyographic (EMG) variables during side-cutting maneuvers.

METHODS

Fifty-seven physically active volunteers were recruited and randomized into two groups: a control group (CG) and an experimental group (EG). The CG maintained their regular physical activity, while the EG followed an individualized, integrated exercise regimen that included strength, neuromuscular, proprioceptive, eccentric training, and whole-body vibration (WBV) exercises, lasting for 12 weeks. EMG-Root Means Square (RMS) values for the quadriceps (Q) and hamstrings (H) were measured immediately following initial foot contact at 50, 100, 150, and 200 milliseconds. Changes in EMG activity were evaluated before and after a twelve-week intervention, and the effect size (ES, 90% confidence limit [90%CL]) was calculated.

RESULTS

The results showed that the EG participants exhibited enhanced co-contraction as measured by the hamstring/quadriceps ratio (H/Q ratio) during both open and cross-cutting side maneuvers after the twelve-week intervention.

CONCLUSION

Furthermore, the customized, integrated exercise program that combined strength, neuromuscular, proprioceptive, eccentric training, and WBV exercises were could potentially serve as a beneficial neuromuscular and biomechanical strategy for addressing knee injury risk in non-professional, physically active populations at high risk for such injuries.

Development and Predictive Validation of the Brazilian Adductor Performance Test for Estimating the Chance of Hip Adductor Injuries in Elite Soccer Athletes

PURPOSE

To develop and validate the Brazilian Adductor Performance Test (BAPT) for predicting hip adductor muscle injuries in elite soccer athletes.

METHODS

A total of 108 soccer athletes were assessed, followed up for 3 months, and evaluated for a history of adductor injury 6 months before BAPT evaluation. The Shapiro-Wilk test was used as the normality test. The Mann-Whitney U test was used to compare BAPT scores between injured and uninjured athletes. Binary logistic regression was performed to identify the athletes' chances of injury based on their BAPT scores. A receiver operating characteristic curve was used to determine the cutoff point for the number of repetitions in the BAPT and Spearman bivariate correlation and identify factors potentially related to the test score. Furthermore, the intraclass correlation coefficient was used to determine interexaminer agreement. The level of significance was set at 95%.

RESULTS

The BAPT scores for hip adductor injury history did not differ significantly (P = .08). A significant deficit was identified in the BAPT scores of the injured athletes at the 3-month follow-up (P = .001). The cutoff point identified was 33 repetitions. Low BAPT scores increased the chance of injury by 20% (odds ratio, 1.20%; P = .001). The interexaminer agreement was .96 (P = .001).

CONCLUSION

BAPT can be used to identify athletes most likely to sustain hip adductor muscle injuries, indirectly reducing the rate of this injury in soccer clubs.

Posturography measures in specific ballet stance position discriminate ballet dancers with different occurrences of musculoskeletal injuries

BACKGROUND

This study aimed to identify the postural sway variables that can distinguish between ballet dancers with high and low occurrences of musculoskeletal injuries.

METHODS

Fourteen professional ballet dancers were assigned to a high-occurrence group (N = 5, reports >2 injuries in the previous 6-months) or a low-occurrence group (N = 9, reports ≤1 injury). Center-of-pressure (COP) data were acquired using a force platform during the following tasks: single-leg stance with eyes open, single-leg stance with eyes closed, and demi-pointe stance with eyes open. The COP standard deviation (SD) and range (RA) in both the medial-lateral (ML) and anterior-posterior (AP) directions were estimated. Between-group comparisons were made through Welch's t-tests for unequal sample size along the effect size measure (Cohen's d). Spearman's rho was used to estimate the association between the number of injuries and the COP variables. The statistical threshold was set at 1%.

RESULTS

A between-group effect was found only for the demi-pointe stance, with large effects for SDML (P = 0.006, d = 1.7), RAAP (P = 0.006, d = 1.7), and RAML (P = 0.005, d = 1.7). An inverse relationship was found between the number of injuries and the demi-pointe's COP range in both directions (Spearman's rho from -0.681 to -0.726, P = 0.007).

CONCLUSIONS

COP measures taken in ballet-specific positions can distinguish between dancers with a high and low occurrence of musculoskeletal injuries. Suggestions are made to include ballet-specific tasks in the functional assessments of professional dancers.

Is it Time to Consider Quaternary Injury Prevention in Sports?

Prevention has traditionally been categorized into three main areas: primary, secondary, and tertiary. In this Current Opinion, we present and discuss the concept of quaternary prevention in sports. Quaternary prevention aims to protect individuals from interventions that likely cause more harm than good, such as overdiagnosis, overtreatment, and overmedication. It includes preventing all types of harm associated with training and clinical interventions. Therefore, any sports injury prevention model or strategy should acknowledge the risks associated with training-related (i.e., overreaching and overuse) and clinical-related (i.e., overdiagnosis, over medicalization, and overtreatment) features. We propose a conceptual framework that integrates quaternary prevention into the contemporary injury prevention models in sports, taking into account that injury prevention is just one branch of the managerial, decision-making, and active hazard control process of risk management that athletes, coaches, and health and performance staff need to deal with. Therefore, we argue that integrating the concept of quaternary prevention into any form of prevention will significantly protect athletes from excessive, inappropriate, and ethically questionable interventions that may likely cause more harm than good.

Using an Affordable Motion Capture System to Evaluate the Prognostic Value of Drop Vertical Jump Parameters for Noncontact ACL Injury

BACKGROUND

Knee kinematic parameters during a drop vertical jump (DVJ) have been demonstrated to be associated with increased risk of noncontact anterior cruciate ligament (ACL) injury. However, standard motion analysis systems are not practical for routine screening. Affordable and practical motion sensor alternatives exist but require further validation in the context of ACL injury risk assessment.

PURPOSE/HYPOTHESIS

To prospectively study DVJ parameters as predictors of noncontact ACL injury in collegiate athletes using an affordable motion capture system (Kinect; Microsoft). We hypothesized that athletes who sustained noncontact ACL injury would have larger initial and peak contact coronal abduction angles and smaller peak flexion angles at the knee during a DVJ.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

102 participants were prospectively recruited from a collegiate varsity sports program. A total of 101 of the 102 athletes (99%) were followed for an entire season for noncontact ACL injury. Each athlete performed 3 DVJs, and the data were recorded using the motion capture system. Initial coronal, peak coronal, and peak sagittal angles of the knee were identified by our software.

RESULTS

Five of the 101 athletes sustained a noncontact ACL injury. Peak coronal angles were significantly greater and peak sagittal flexion angles were significantly smaller in ACL-injured athletes (P = .049, P = .049, respectively). Receiver operating characteristic (ROC) analysis demonstrated an area under the curve of 0.88, 0.92, and 0.90 for initial coronal, peak coronal, and peak sagittal angle, respectively. An initial coronal angle cutoff of 2.96° demonstrated 80% sensitivity and 72% specificity, a peak coronal angle cutoff of 6.16° demonstrated 80% sensitivity and 72% specificity, and a peak sagittal flexion cutoff of 93.82° demonstrated 80% sensitivity and 74% specificity on the study cohort.

CONCLUSION

Increased peak coronal angle and decreased peak sagittal angle during a DVJ were significantly associated with increased risk for noncontact ACL injury. Based on ROC analysis, initial coronal angle showed good prognostic ability, whereas peak coronal angle and peak sagittal flexion provided excellent prognostic ability. Affordable motion capture systems show promise as cost-effective and practical options for large-scale ACL injury risk screening.

Serial Subtraction Alters Lateral Step-down Tibiofemoral Kinematics in Healthy Adults

This study evaluated the effects of two types of cognitive dual-tasking on three-dimensional knee kinematics during the lateral step-down. 19 healthy individuals (22.05±1.61 yrs., 173.92±9.21 cm, 67.99±12.65 kg) participated in this study. Participants completed 5 repetitions of a lateral step-down task for each leg and each testing condition (control, Stroop, and serial subtraction by seven). An electromagnetic motion sensor was attached to the femur via compression clamp placed about the medial and lateral epicondyles. Another sensor was attached 2 cm below the ipsilateral tibial tuberosity. A custom MATLAB algorithm located the knee joint axis of rotation from dynamic knee flexion and extension. Discrete kinematics at peak flexion were used in this study. Paired samples t-tests were used to compare average frontal, transverse, and sagittal plane knee position at maximum flexion between conditions for each leg. No significant differences were found for either limb between control and Stroop conditions. Comparisons revealed significant differences in frontal and transverse plane knee angles at peak flexion between the control and serial subtraction by seven conditions. These findings indicate serial subtraction by seven requires different cognitive processing abilities which may cause greater interference with some aspects of motor control.

The effects of plyometric jump training on physical fitness attributes in basketball players: A meta-analysis

BACKGROUND

There is a growing body of experimental evidence examining the effects of plyometric jump training (PJT) on physical fitness attributes in basketball players; however, this evidence has not yet been comprehensively and systematically aggregated. Therefore, our objective was to meta-analyze the effects of PJT on physical fitness attributes in basketball players, in comparison to a control condition.

METHODS

A systematic literature search was conducted in the databases PubMed, Web of Science, and Scopus, up to July 2020. Peer-reviewed controlled trials with baseline and follow-up measurements investigating the effects of PJT on physical fitness attributes (muscle power, i.e., jumping performance, linear sprint speed, change-of-direction speed, balance, and muscle strength) in basketball players, with no restrictions on their playing level, sex, or age. Hedge's g effect sizes (ES) were calculated for physical fitness variables. Using a random-effects model, potential sources of heterogeneity were selected, including subgroup analyses (age, sex, body mass, and height) and single training factor analysis (program duration, training frequency, and total number of training sessions). Computation of meta-regression was also performed.

RESULTS

Thirty-two studies were included, involving 818 total basketball players. Significant (p < 0.05) small-to-large effects of PJT were evident on vertical jump power (ES = 0.45), countermovement jump height with (ES = 1.24) and without arm swing (ES = 0.88), squat jump height (ES = 0.80), drop jump height (ES = 0.53), horizontal jump distance (ES = 0.65), linear sprint time across distances ≤10 m (ES = 1.67) and >10 m (ES = 0.92), change-of-direction performance time across distances ≤40 m (ES = 1.15) and >40 m (ES = 1.02), dynamic (ES = 1.16) and static balance (ES = 1.48), and maximal strength (ES = 0.57). The meta-regression revealed that training duration, training frequency, and total number of sessions completed did not predict the effects of PJT on physical fitness attributes. Subgroup analysis indicated greater improvements in older compared to younger players in horizontal jump distance (>17.15 years, ES = 2.11; ≤17.15 years, ES = 0.10; p < 0.001), linear sprint time >10 m (>16.3 years, ES = 1.83; ≤16.3 years, ES = 0.36; p = 0.010), and change-of-direction performance time ≤40 m (>16.3 years, ES = 1.65; ≤16.3 years, ES = 0.75; p = 0.005). Greater increases in horizontal jump distance were apparent with >2 compared with ≤2 weekly PJT sessions (ES = 2.12 and ES = 0.39, respectively; p < 0.001).

CONCLUSION

Data from 32 studies (28 of which demonstrate moderate-to-high methodological quality) indicate PJT improves muscle power, linear sprint speed, change-of-direction speed, balance, and muscle strength in basketball players independent of sex, age, or PJT program variables. However, the beneficial effects of PJT as measured by horizontal jump distance, linear sprint time >10 m, and change-of-direction performance time ≤40 m, appear to be more evident among older basketball players.

Establishing Normative Dynamic Postural Control Values in Elite Female Handball Players

Background

Lower extremity injuries among young female handball players are very common. The modified Star Excursion Balance Test (mSEBT) is a valid clinical tool to assess dynamic postural control and identify athletes with higher risk of injury. However, its interpretation is difficult since performance on this test is highly sport dependent. No normative values on the mSEBT exist in handball.

Purpose

The aim of this investigation was to establish normative ranges of mSEBT performance in young, healthy female handball players to help practitioners when interpreting risk estimates.

Study design

Cross-Sectional Study.

Methods

Athletes from 14 elite teams were recruited during a national tournament and performed 3 trials in the anterior (ANT), posteromedial (PM), posterolateral (PL) directions of the mSEBT. Means, standard deviations and 95% confidence intervals (95%CI) of normalized reached distances were calculated for each direction and the composite score (COMP). Level of asymmetry between dominant and non-dominant limbs were calculated for each direction using Bland Altman analyses. Group differences were weighed against the established mSEBT minimum detectable differences (MDD) to compare scores between limbs and across different player positions.

Results

One-hundred and eighty-eight females (16.8±0.9 years) were tested. Mean reach distances were 65.2±5% (64.7-65.7), 110.0±6.2% (109.3-110.6), 107.1±6.2% (106.5-107.8) and 94.1±4.9% (93.6-94.6) for the ANT, PM, PL directions and COMP score respectively. Bias and limits of agreement for limb asymmetry were -0.23% (-5.85%, 5.38%) for ANT, -0.83% (-8.80%, 7.14%) for PM, 0.33% (-8.51%, 9.17%) for PL and -0.27% (-4.88%, 4.33%) for COMP score. No meaningful differences were observed between limbs or across player positions since the values did not exceed the MDD and all 95%CIs overlapped.

Conclusion

This study provides normative performance values for dynamic postural control as measured by the mSEBT among young, healthy, elite female handball players. Considering the high incidence of injury in this population, these values can be used for injury risk reduction and return to sport decisions. Further prospective studies are needed to established specific cut-off scores in this population.

Level of evidence

2c.

Validity of the frame subtraction method in dynamic postural stability

Background

The movement of targeted subjects can be calculated using the frame subtraction method. However, the validity of this evaluation method of dynamic postural stability has not been clarified yet. This study aimed to verify the validity of the evaluation method for jump landing using the frame subtraction score based on the ground reaction force (GRF).

Methods

Twenty subjects performed single-leg jump landing, and their dynamic postural stability index (DPSI), medial‒lateral stability index (MLSI), anterior‒posterior stability index, and vertical stability index (VSI) were calculated from the GRF. Simultaneously, motion images were captured using digital video cameras in the sagittal and frontal planes. After the motion images were analyzed using the frame subtraction method, the frame subtraction scores in the frontal, sagittal, and combined planes were calculated. To confirm its validity, the relationship between the frame subtraction scores and GRF parameters was investigated using Pearson's correlation analysis.

Results

The frame subtraction scores in the frontal and combined planes were significantly correlated with the DPSI, MLSI, and VSI (r = 0.46–0.75, P < 0.05).

Conclusions

Therefore, the frame subtraction method could be applied to the evaluation of dynamic postural stability. Markerless systems are deemed useful in clinical practice.

Effects of age, sex and task on postural sway during quiet stance

BACKGROUND

Postural sway during quiet standing has been shown as a useful task to assess risk of falling in older adults. While the risk of falling is consistently reported to be higher in older females than males, the sex-related differences in postural sway are not consistent across the studies.

RESEARCH QUESTION

What are the effects of age and sex on postural sway during quiet standing during different stance conditions?

METHODS

We examined the effects of age (40 young and 34 older adults), sex (37 males and 37 females), and their interaction on the postural sway during different stance conditions. We compared the center of pressure (CoP) velocity, amplitude and frequency during parallel (eyes open and eyes closed) and semi-tandem (eyes open) stances.

RESULTS

Our results suggest that postural sway is similar between sexes in young participants, while older males exhibit larger postural sway than older female participants (10/21 outcomes). Older female participants exhibited lower CoP amplitude (but larger total and anterior-posterior CoP velocity) compared to young female participants. We also found that the increase in the postural sway with increasing task difficulty is more pronounced in older vs. young adults.

SIGNIFICANCE

This study shows that ageing-related changes in postural sway are sex- and task-specific. Researchers and clinicians need to be aware of these effects when comparing groups or monitoring changes in time.

Acute Effects of Tissue Flossing Coupled with Functional Movements on Knee Range of Motion, Static Balance, in Single-Leg Hop Distance, and Landing Stabilization Performance in Female College Students

Flexibility, specifically that in the amplitude of sagittal-plane range of motion (ROM), can improve jump landing patterns and reduce the potential for sports injury. The use of floss bands (FLOSS) reportedly increases joint range of motion (ROM) in the shoulder, ankle, and elbow joints. However, little research on the effectiveness of FLOSS on the knee joint has been conducted. This study investigated the effects of FLOSS on knee ROM, static balance, single-leg-hop distance, and landing stabilization performance in women. This study had a crossover design. Twenty active female college students without musculoskeletal disorders were randomly assigned to receive a FLOSS intervention or elastic bandage (ELA) control on their dominant knees. The participants underwent FLOSS and ELA activities on two occasions with 48 h of rest between both sets of activities. The outcomes were flexibility of the quadriceps and hamstrings, how long one could maintain a single-leg stance (with and without eyes closed), distance on a single-leg triple hop, and score on the Landing Error Scoring System (LESS); these outcomes were evaluated at preintervention and postintervention (immediately following band removal and 20 min later). After the FLOSS intervention, the participants’ hamstring flexibility improved significantly (immediately after: p = 0.001; 20 min later: p = 0.002), but their quadricep flexibility did not. In addition, FLOSS use did not result in worse single-leg stance timing, single-leg triple-hop distance, or landing stabilization performance relative to ELA use. Compared with the ELA control, the FLOSS intervention yielded significantly better LESS at 20 min postintervention (p = 0.032), suggesting that tissue flossing can improve landing stability. In conclusion, the application of FLOSS to the knee improves hamstring flexibility without impeding static balance, and improves single-leg hop distance and landing stabilization performance in women for up to 20 min. Our findings elucidate the effects of tissue flossing on the knee joint and may serve as a reference for physiotherapists or athletic professionals in athletic practice settings.

The Hamstring and ACL Injury Incidence during a Season Is Not Directly Related to Preseason Knee Strength Ratios in Elite Male Soccer Players

Background and Objectives: The aim of this study was to identify preseason isokinetic strength differences in the knee flexors and extensors and their ipsilateral/bilateral ratios and, furthermore, to compare the results among players who subsequently overcame a hamstring strain injury (HSI) or anterior cruciate ligament (ACL) rupture during the season and those who did not. Materials and Methods: A total of 134 professional soccer players underwent isokinetic strength assessment at a velocity of 60°·s−1 (knee flexors and extensors) for the dominant and non-dominant lower limb to determine preseason peak torque values and bilateral and ipsilateral strength ratios. Subsequently, the incidence of injuries during the season was recorded, and players were divided into groups according to ACL rupture injuries (n = 10), hamstring strains (n = 10), and a control group of non-injured players who were selected on a random basis (n = 20). A retrospective approach was used to analyze and compare the preseason strength characteristics and whether some variance among groups was relevant among the injured leg and non-injured leg groups. Results: The results of our study show that low-angular velocity preseason testing did not result in a player’s HSI or ACL injury during the season. The difference between the monitored groups ranged from 1.5% to 3%. The comparison showed low evidence for significant differences. Conclusions: An angular velocity of 60°·s−1 within concentric muscle contraction alone was not linked to subsequent injury of the hamstring or anterior cruciate ligament and acted as an insufficient factor of injury risk in adult professional soccer players.

Center of pressure-based postural sway differences on parallel and single leg stance in Olympic deaf basketball and volleyball players

In sports such as basketball and volleyball, loss of balance due to the inability to maintain body stability and lack of postural control adversely affect athletic performance. Deaf athletes appear to struggle with balance and postural stability problems. The purpose of this study was to examine postural sway values in parallel and single leg stance of Olympic deaf basketball and volleyball players and reveal differences between the branches. Twenty-three male athletes from the Turkish national deaf basketball (n=11) and volleyball (n=12) teams participated in the study. After anthropometric measurements, the subjects completed postural sway (PS) tests in parallel/single leg stances with open eyes and closed eyes on a force plate. PS parameters (sway path, velocity, and area) obtained from the device software were used for the statistical analysis. The Mann-Whitney U-test was used to compare differences in PS parameters between basketball and volleyball players, and the alpha value was accepted as 0.05. Volleyball players had significantly better results in parallel stance and dominant leg PS values than basketball players (P<0.05). There was no significant difference between the groups in nondominant leg PS values (P>0.05). We think that proprioceptive and vestibular system enhancing training practices to be performed with stability exercises will be beneficial in terms of both promoting functional stability and interlimb coordination. Trainers and strength coaches should be aware of differences in the postural control mechanism of deaf athletes.

Injury History and Perceived Knee Function as Risk Factors for Knee Injury in Youth Team-Sports Athletes

BACKGROUND

The identification of risk factors for sports injuries is essential before injury prevention strategies can be planned.

HYPOTHESIS

Previous acute knee injury and lower perceived knee function measured by Knee injury and Osteoarthritis Outcome Score (KOOS) will increase the risk of acute knee injury in youth team-sports athletes.

STUDY DESIGN

Prospective cohort study.

LEVEL OF EVIDENCE

Level 3.

METHODS

At baseline, youth (≤21 years old) male and female basketball and floorball athletes completed a questionnaire on previous acute knee injuries and perceived knee function (KOOS). A total of 211 male and 183 female athletes were followed for an acute knee injury up to 3 years. Unadjusted and adjusted Cox regression models were used in risk factor analyses.

RESULTS

In male athletes, previous acute knee injury and lower KOOS Pain, Activities of Daily Living, Sport and Recreation, and knee-related Quality of Life subscale scores increased the risk of acute knee injury in the unadjusted analyses. Adjusted analyses for male injuries were not performed because of low number of acute knee injuries (n = 18). In female athletes, previous acute knee injury increased the risk of acute knee injury when adjusted for athletes' age and body mass index (hazard ratio, 2.6 [95% CI, 1.3-5.2]). In female athletes, none of the KOOS subscale scores were associated with the increased risk of acute knee injury in the adjusted analyses.

CONCLUSION

Previous acute knee injury was associated with the risk of new acute knee injury in youth male and female athletes. In youth male athletes, additionally, lower perceived knee function in 4 out of 5 KOOS subscale scores were associated with the increased risk of new acute knee injury.

CLINICAL RELEVANCE

The treatment and rehabilitation of the present acute knee injury and secondary prevention of reinjury should be emphasized in youth team-sports athletes.

Can a Modified Y-Balance Test Predict Running Overuse Injuries over the Course of a Division I Collegiate Cross-Country Season?

BACKGROUND

Collegiate distance runners often suffer from running overuse injuries (ROI). The Y-Balance Test (YBT) has the potential to predict ROI risk in collegiate runners.

PURPOSE

To investigate whether a preseason clinical assessment of dynamic balance, through a modified version of the YBT (mYBT), can predict risk of ROIs during one NCAA Division I cross-country (XC) season.

STUDY DESIGN

Prospective case-control study.

METHODS

Participants from a Division I XC team were screened for mYBT performance in four directions: anterior (AN), posteromedial (PM), posterolateral (PL), and posterior (PO). ROIs were tracked over the course of the XC season. Receiver operating characteristic (ROC) curve analysis (α = 0.05) was utilized to investigate the effectiveness of the mYBT in predicting injury risk.

RESULTS

Nine (5 female, 4 male) of 29 runners developed an ROI during the XC season. Five components of the mYBT were found to predict injuries, including normalized nondominant PO score (AUC = 0.756, p = 0.03; RR = 1.90), AN raw difference and limb asymmetry (AUC = 0.808, p = 0.01), and PM raw difference and limb asymmetry in males (AUC = 0.958, p = 0.02).

CONCLUSION

Specific components of the mYBT can help predict the risk of developing a running overuse injury over one Division I XC season.

LEVEL OF EVIDENCE

Screening, Level 3.

The effects of leg preference and leg dominance on static and dynamic balance performance in highly-trained tennis players

In this study, 90 (51 males, 39 females) tennis players performed single-leg quiet stance and single-leg landing tasks. For the static standing task, center-of pressure (CoP) velocities, amplitudes, frequency and area were calculated. For the landing tasks, time to stabilization as well as dynamic postural stability index were considered. The analysis of differences between the legs was done based on two methods for a priori determination of leg preference, one based on the preference of kicking a ball and one based on the preference for single-leg jumping. An additional analysis was done based on the leg dominance (determined post hoc), based on the observed performance of the tasks. In case of the classification based on kicking a ball, there was a statistically significantly lower CoP anterior-posterior velocity and anterior-posterior amplitude in static balance task (p ≤ 0.017; 0.17 ≤ d ≤ 0.28) for the preferred leg. The CoP frequency was higher in the preferred leg for both directions (p ≤ 0.002; 0.10 ≤ d ≤ 0.22). For the landing task, CoP medial-lateral time to stabilization was statistically significantly shorter for the preferred leg (0.28 ± 0.38 s) compared to the non-preferred leg (0.47 ± 0.60 s) (p = 0.012; d = 0.38). There were no differences between the legs for the landing task. Moreover, there were no differences between the legs when we used the preference based on jumping for either of the tasks (d ≤ 0.14). The differences between legs in terms of observed dominance were larger than the differences based on the preference, which stresses the need for clear distinction of limb preference and limb dominance in research and practice. Regarding the effect of leg preference, small differences in static balance may exist between the legs (when the preference is based on kicking a ball).

Establishing Reference Values for Isometric Knee Extension and Flexion Strength

Single-joint isometric and isokinetic knee strength assessment plays an important role in strength and conditioning, physical therapy, and rehabilitation. The literature, however, lacks absolute reference values. We systematically reviewed the available studies that assessed isometric knee strength. Two scientific databases (PubMed and PEDro) were searched for the papers that are published from the inception of the field to the end of 2019. We included studies that involved participants of both genders and different age groups, regardless of the study design, that involved isometric knee extension and/or flexion measurement. The extracted data were converted to body-mass-normalized values. Moreover, the data were grouped according to the knee angle condition (extended, mid-range, and flexed). A meta-analysis was performed on 13,893 participants from 411 studies. In adult healthy males, the pooled 95% confidence intervals (CI) for knee extension were 1.34–2.23Nm/kg for extended knee angle, 2.92–3.45Nm/kg for mid-range knee angle, and 2.50–3.06Nm/kg for flexed knee angle, while the CIs for flexion were 0.85–1.20, 1.15–1.62, and 0.96–1.54Nm/kg, respectively. Adult females consistently showed lower strength than adult male subgroups (e.g., the CIs for knee extension were 1.01–1.50, 2.08–2.74, and 2.04–2.71Nm/kg for extended, mid-range, and flexed knee angle condition). Older adults consistently showed lower values than adults (e.g., pooled CIs for mid-range knee angle were 1.74–2.16Nm/kg (male) and 1.40–1.64Nm/kg (female) for extension, and 0.69–0.89Nm/kg (male) and 0.46–0.81Nm/kg (female) for flexion). Reliable normative for athletes could not be calculated due to limited number of studies for individual sports.

The Star Excursion Balance Test: An Update Review and Practical Guidelines

The Star Excursion Balance Test (SEBT) is a reliable, responsive, and clinically relevant functional assessment of lower limbs’ dynamic postural control. However, great disparity exists regarding its methodology and the reported outcomes. Large and specific databases from various population (sport, age, and gender) are needed to help clinicians when interpreting SEBT performances in daily practice. Several contributors to SEBT performances in each direction were recently highlighted. The purpose of this clinical commentary is to (a) provide an updated review of the design, implementation, and interpretation of the SEBT and (b) propose guidelines to standardize SEBT procedures for better comparisons across studies.

Screening Tools as a Predictor of Injury in Gymnastics: Systematic Literature Review

Background

Gymnastics requires a high level of physical ability and technical skill which utilises short sets of athleticism and artistry to perform complex and intense movements which can overload musculoskeletal tissues and result in acute injuries which can develop into chronic injuries. The aim of this systematic literature review was to investigate which screening tools predict injury in gymnasts and encompasses all genres, levels and ages.

Methods

An electronic search of seven databases from their inception until March 2021 was conducted. The databases were the Allied and Complementary Medicine Database, CINAHL, eBook Collection (EBSCOhost), MEDLINE, Cochrane Database of Systematic Reviews, SPORTDiscus and PEDro (the Physiotherapy Evidence Base). A combination of the following search terms was used: (1) Gymnastics AND injury AND Screening, (2) Screening AND Gymnastics and (3) Musculoskeletal AND Screening AND Gymnastics. These terms were searched in all text, abstract, title and subject terms. Studies were assessed using a 20-point scoring tool.

Results

The mean methodological quality score was 13.1 points (range 10–17 points). Range of motion, anthropometric and postural measurements, hypermobility, clinical diagnostic tests, movement screening tools, muscle strength, power and endurance were reported in the included studies. Some evidence existed for screening measurement of height and mass as taller and heavier gymnasts might be more susceptible to injury; however, the different methodologies utilised and lack of acknowledgment of confounding variables limit the clinical relevance of these findings.

Conclusions

Height and mass should be recorded during the screening process. A lack of heterogeneity in study methodology prevented a meta-analysis. Studies were limited by a lack of prospective injury design, poor injury definition, self-reporting of injury and only 2 studies reported reliability of screening tools. Further research is required to determine the role of injury screening in gymnastics.

Registration: The review protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO) with the registration number CRD42020218339.

How injury registration and preseason assessment are being delivered: An international survey of sports physical therapists

OBJECTIVE

To identify the role of sports physical therapists (PT) in the organization of injury registration and preseason assessment, applied in athletic organizations and sports teams of different gender and level world-wide.

DESIGN

cross-sectional study.

SETTING

LimeSurvey platform.

PARTICIPANTS

Sports PTs working with athletes invited through International Federation of Sports Physical Therapy.

MAIN OUTCOME MEASURES

injury registration and athlete's screening.

RESULTS

414 sports PTs participated in this international survey (mean age of 37.66 (SD = 9.38) years). 340 participants indicated that the PT as the responsible for injury registration. Barriers to properly register injury throughout the season were indicated by 157 sports PT and 86 (54.77%) indicated a lack of time on their routine as the main factor. 93 participants (30.09%) indicated that they customize the prevention program based on the preseason assessment. Sports PTs who reported not performing a preseason assessment (92 participants - 22.22%) mainly indicated this to be consequence of lack of structure in the organization (44 participants - 47.82%).

CONCLUSION

The majority of the sports PTs participate on injury registration and perform preseason assessment in athletes. However, lack of time in their routine and structure in the organization were recognized as the most important barriers to organize these properly.

The Functional Movement Screen as an injury prediction tool for German physical education and exercise science students: a prospective cohort-study

Background Several studies have evaluated the applicability of the Functional Movement Screen (FMS) as a screening tool for injury prediction. However, only few studies investigate gender differences for FMS as a screening tool for female and male college students.

Objective To evaluate gender differences in FMS single items and the overall score. In addition, the applicability of FMS as a diagnostic tool for injury prevention of German exercise students will be investigated.

Method N = 99 college students performed an FMS at the beginning of the semester. Injuries were recorded for the entire term. Gender differences of FMS single items were assessed using the Mann-Whitney-U-Test. Differences in injury prediction were calculated using logistic regression. If the model was statistically significant, diagnostic accuracy was calculated using receiver operating characteristic (ROC) curves and the area under the curve (AUC). The Youden index was used to identify a cut-off score. 2 × 2 contingency tables, sensitivity and specifity, positive/negative predictive values, and likelihood ratios were assessed.

Results There were significant gender differences for Deep Squat, Shoulder Mobility, Trunk Stability Push Up, and Active Straight Leg Raise. The logistic regression showed that the composite score was statistically significant in clarifying the model for females (p = 0.005, RN 2 = 0.14), but not for males (p = 0.18, RN 2 = 0.04). The ROC curve indicated acceptable injury prediction in females (AUC: 0.66, p = 0.02) and poor injury prediction in males (AUC: 0.40, p = 0.19). The cut-off score of ≤ 16 for females resulted in a sensitivity of 63 % and specificity of 54 %. No cut-off score was calculated for males.

Conclusion Females performed better on flexibility items, while males scored higher on strength exercises. Results of the study indicate low predictive accuracy. Therefore, no solid recommendation can be made for the use of the FMS as an injury screening tool for either female or male German exercise science students.

How injury prevention programs are being structured and implemented worldwide: An international survey of sports physical therapists

OBJECTIVE

To identify the role of sports physical therapists (PT) in the injury prevention process and to compare the structure of preventive programs and associated (organization) policies applied in athletic organizations and sports teams of varying gender and level world-wide.

DESIGN

cross-sectional study.

SETTING

LimeSurvey platform.

PARTICIPANTS

Sports PT working with athletes invited through the International Federation of Sports Physical Therapy.

MAIN OUTCOME MEASURES

Sports injury prevention program (IPP) structure and implementation.

RESULTS

414 participants fully participate in this survey study. Athlete's injury history (68.84%), the most common injuries within the sport modality (67.87%) and athlete's preseason screening results (64.01%) were most frequently used to customize IPPs. Warm-up (70.04%) and individually PT-guided exercise-therapy (70.04%) were the preferred methods to organize the prevention routine. The main barrier for IPP implementation was lack of time within the athlete's weekly training schedule (66.66%). The majority of the participants (72.84%) reported to evaluate the perception of IPP's effect by comparing current and preceding seasons' injury occurrences.

CONCLUSION

These survey results are the first identifying contemporary sports injury prevention organization and implementation policies on an international level. This information might support the sports PT community in improving and standardizing IPP (implementation) strategies worldwide.

Quadriceps strength asymmetry as predictor of ankle sprain in male volleyball players

BACKGROUND

Ankle sprain is the most common acute time-loss injury in volleyball and occurs mainly during landing from a jump. Therefore we have evaluated the role of quadriceps strength and countermovement jump height on ankle sprain occurrence, as these intrinsic modifiable risk factors were not yet evaluated. We have also hypothesised that presence of quadriceps strength asymmetry could be a possible risk factor for ankle sprains in male volleyball players.

METHODS

This was a prospective cohort study. Male volleyball players (N = 99) from Slovenian national league participated in the study. Before the start of the season, all participants completed a preseason questionnaire and underwent evaluation of vertical jump performance and bilateral isokinetic strength of the quadriceps (Q) and hamstrings (H). During the subsequent season the players reported acute time loss injuries because of ankle sprain through a weekly questionnaire.

RESULTS

We have registered 19 ankle sprains during the season. Overall ankle sprain incidence was 0.41±0.24 per 1000 h. Previous ankle sprain (odd ratio 0.86; 95% CI 0.25 - 2.89, p = 0.802) and jump height (1.05; 95% C.I. 0.94 - 1.19, p = 0.393) were not significant risk factors, while Q strength asymmetry was a significant predictor of an ankle sprain (odd ratio 0.956; 95% CI 0.919-0.995, p = 0.026). Compared with the uninjured players, the injured players had higher right concentric Q strength, higher Q strength asymmetry, and lower concentric right H-Q strength ratio (all p<0.03).

CONCLUSIONS

Our results suggest that excessive concentric strength of the right Q, which leads to low H-Q strength ratio, and high bilateral Q strength asymmetry in favor of the right side, could be associated with increased risk of ankle sprains in male volleyball.

Transient characteristics of body sway during single-leg stance in athletes with a history of ankle sprain

BACKGROUND

The role of the measurements of postural stability in the context of screening for ankle sprain risk is still equivocal. Transient characteristics of body sway have been suggested as an alternative or an improvement to traditional whole-trial analyses.

RESEARCH QUESTION

Are transient characteristics of body sway sensitive to the history of ankle sprain?.

METHODS

The assessment of 30-s single-leg body sway was performed on a group of 93 athletes from basketball, soccer, tennis and running who reported at least 1 ankle sprain in the last 12 months, while a group of 244 athletes from the same disciplines served as a control group without an ankle sprain reported for the same time period. We considered the mean center-of-pressure (CoP) velocity, CoP amplitude and CoP frequency. In addition to traditional whole-trial variables, we calculated the relative differences between the 1 st and the 2nd (DIF_21) and 1 st and 3rd (DIF_31) 10-s time intervals within the whole trial.

RESULTS

The indexes of transient characteristics of body sway (i.e., the DIF_21 and DIF_31) were in trivial or weak correlations with whole-trial variables (all r ≤ 0.29). Athletes with ankle sprain history exhibited smaller CoP ML velocity (p = 0.002) and larger CoP ML frequency (p = 0.001). In the injured group, the injured leg exhibited lower total and medial-lateral (ML) CoP velocity (p = 0.005-0.040), as well as lower CoP ML amplitude (p = 0.002) and higher CoP ML frequency (p = 0.010). The transient characteristics of body sway (DIF_21 and DIF_31) were very similar between the groups and between the injured and uninjured legs.

SIGNIFICANCE

Transient characteristics of body sway do not appear to differentiate the athletes with and without a history of ankle sprain. Further research is needed to confirm if the transient characteristics of body sway could be used for detection of risk of falls in older adults or assessment of athletic performance.

Preseason functional testing in young basketball players: asymmetries and intercorrelations

[Purpose] The present study aimed to examine the existence and degree of possible asymmetries of functional test performance and their intercorrelations in the lower extremities of young basketball players. [Participants and Methods] Twenty-seven healthy male basketball players (age: 15.52 ± 1.37 years) were examined for the symmetric function of their lower extremities using triple hop for distance tests in the sagittal and frontal plane (medial-lateral), the Y-balance test and a vertical jump test. [Results] Participants exhibited statistically significant side-to-side differences in only the medial triple hop test, as they jumped further on their non-dominant for stability lower limb. No other asymmetries were observed in the rest of the functional tests. Significant correlations were also indicated between the vertical jumptest and the three directions of the triple hop test for both lower limbs. [Conclusion] Our findings proved that young basketball players present a symmetrical picture of functional performance, as revealed by the evaluation of various functional tests. The only significant asymmetric adaptation observed in the medial triple hop test will have to be strengthened by future studies to be implemented in injury prevention programs.

Systematic review of screening tools for common soccer injuries and their risk factors

Background

Several screening tools are available for use in a clinical setting to predict injury. However, there is a lack of evidence regarding the accuracy of these tools to predict soccer-specific injuries.

Objectives

The purpose of this systematic literature review was to determine the psychometric properties or accuracy of screening tools for common soccer injuries.

Methods

A systematic review of diagnostic test accuracy was undertaken based on the Joanna Briggs Institute (JBI) procedure for conducting systematic reviews. Databases such as SPORT Discus, Cinahl, Medline, Science Direct, PubMed and grey literature were searched in order to access suitable studies.

Results

A total of 10 studies were included for the analysis – three were analysed quantitatively whilst the remaining seven were analysed qualitatively. The screening tools were of high reliability, sensitivity and specificity (calculated as intraclass correlation coefficient [ICC] (0.68 95% confidence interval [CI]: 0.52–0.84 and 0.64 95% CI: 0.61–0.66, respectively).

Conclusion

The screening tools assessed for the prediction of common soccer injuries that emerged from this systematic review include the Functional Movement Screening (FMS™), the Landing Error Scoring System (LESS), the Tuck Jump Assessment, the Soccer Injury Movement Screening (SIMS) and the conventional hamstrings to quadriceps ratio; all with good evidence of predicting common soccer injuries. These tools were of high sensitivity and specificity thus reliable for soccer screening.

Clinical implications

The validity of these tools is acceptable and therefore the authors recommend that these tools be included in an injury prevention programme for soccer players.

Practicability of lower extremity functional performance tests and their measurement properties in elite athletes: protocol for a systematic review

INTRODUCTION

Lower extremity injury (LEI) is highly prevalent and its occurrence increases the risk of future injury in athletic populations. Identifying athletes at risk of injury is the key to target injury-prevention programmes. Functional performance tests (FPT) assess an athlete's ability to produce and accept forces during movement tasks reflective of those experienced in sport, and are used to identify deficits in physical qualities or neuromuscular control. This review aims to identify FPT which have potential to predict LEI and assess their measurement properties associated with reliability, validity, responsiveness and practicability (interpretability and feasibility).

METHODS/ANALYSIS

This protocol will be reported using the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocol and the COnsensus-based Standards for the selection of health Measurement INstruments Methodology. The search strategy has two stages: stage 1 will identify lower limb FPT used in athletic populations; and stage 2 will assess the measurement properties of the identified FPT. A sensitive search strategy will use MEDLINE, EMBASE, CINHAL and SPORTdiscus databases; from inception to June 2020. Hand searching reference lists, key journals and grey literature will be completed. One reviewer will complete search 1 and data extraction. Two reviewers will complete the search, data extraction and risk-of-bias assessment for search 2. Evidence will be pooled or summarised by individual measurement property by each individual study and grouped by FPT. Meta-analysis using a random effects model with subgroup analysis will be performed where possible. Pooled or summarised results for each FPT in relation to each measurement property will be rated against the criteria for good measurement properties. Two reviewers will assess the overall body of evidence per measurement property per FPT using the modified Grading of Recommendations, Assessment, Development and Evaluation guidelines. This review will enable clinicians to make an informed choice when selecting FPT.

ETHICS AND DISSEMINATION

No ethical approval is required for this review and the results will be disseminated through peer-reviewed publications and submitted for conference presentation.

PROSPERO REGISTRATION NUMBER

CRD42020188932.

Potential prognostic factors for hamstring muscle injury in elite male soccer players: A prospective study

Hamstring injuries remain the most common injury type across many professional sports. Despite a variety of intervention strategies, its incidence in soccer players playing in the UEFA Champions League has increased by 4% per year over the last decade. Test batteries trying to identify potential risk factors have produced inconclusive results. The purpose of the current study was to prospectively record hamstring injuries, to investigate the incidence and characteristics of the injuries, and to identify possible risk factors in elite male soccer players, playing in the Kosovo national premier league. A total of 143 soccer players from 11 teams in Kosovo were recruited. To identify possible prevalent musculoskeletal or medical conditions a widespread health and fitness assessment was performed including isokinetic strength testing, Nordic hamstring strength test, functional tests, and a comprehensive anamnesis surveying previous hamstring injuries. On average 27.9% of the players sustained at least one hamstring injury with three players suffering bilateral strains with the re-injury rate being 23%. Injured players were significantly older and heavier and had a higher body mass index compared to non-injured ones (p < 0.05). There was a lower passing rate in the Nordic hamstring strength test and a higher injury incidence among the previously injured players compared to non-injured ones (p < 0.05). Except for hamstring/quadriceps ratio and relative torque at 60°/sec (p < 0.05) for dominant and non-dominant leg, there were no other significant differences in isokinetic strength regardless of the angular velocity. No differences were observed for functional tests between cohorts. Regression analysis revealed that age, Nordic hamstring strength test, previous injury history, and isokinetic concentric torque at 240°/sec could determine hamstring injuries by 25.9%, with no other significant predicting risk factors. The battery of laboratory and field-based tests performed during preseason to determine performance related skills showed limited diagnostic conclusiveness, making it difficult to detect players at risk for future hamstring injuries.

Neuromuscular training for the prevention of ankle sprains in female athletes: a systematic review

Ankle sprains are a common sports-related injury, and female athletes are more likely to sustain this injury than their male counterparts. Previous reviews have evaluated the efficacy of prevention programs in reducing ankle sprains in athletes, but no reviews have specifically focused on female athletes. The objective of this systematic review was to examine the sex-specific effectiveness of neuromuscular training (NMT) programs in reducing the risk of ankle sprains in female athletes. A search of PubMed, Ovid Medline, Embase, and Web of Science databases was performed using the terms: (proprioception OR proprioceptive OR balance OR neuromuscular OR stability OR sensorimotor) AND training AND (ankle sprain OR ankle injury OR inversion injury OR ankle instability) AND (sport* OR athlet* or basketball OR volleyball OR soccer OR handball OR tennis OR netball OR hockey OR softball OR gymnastics OR danc* OR ballet OR cheerlead*) AND (female OR women OR girl). Studies selected for inclusion were written in English, evaluated female athletes in organized athletics or reported female-specific data for mixed-sex cohorts, included a non-NMT comparison, and used ankle injury rate outcome measures. Seven articles were selected for inclusion, which evaluated a combined 5,187 female basketball, handball, volleyball, soccer, and floorball players. Two studies reported significant differences between NMT participants and controls, concluding the greatest effects were observed in preventing non-contact ankle sprains. The remaining 5 studies, although not statistically significant, revealed an evident trend toward the efficacy of ankle injury prevention with NMT programs. Current available evidence supports the efficacy of NMT in preventing ankle sprains in female athletes. When designing NMT programs, investigators should consider utilizing comprehensive approaches that incorporate strength, balance, plyometric, and agility training as the studies with significant findings created comprehensive NMT programs. Further investigations into sport- and female-specific programs are warranted.

Infrared Thermography Protocol on Reducing the Incidence of Soccer Injuries

Context: Infrared thermography has been used to detect skeletal muscle overload and fatigue in athletes, but its use in injury prevention in professional soccer has not been studied to date. Objectives: To establish a novel injury prevention program based on infrared thermography and to determine its influence on the injury incidence in professional soccer players in the preseason. Design: A cross-sectional, prospective study design was used to compare a conventional injury prevention program (CPP) applied over the first preseason and an infrared thermography injury prevention program (IRTPP) carried out in the following preseason. Setting: Soccer training ground. Participants: Twenty-four players belonging to a first division soccer team from Spain. Main Outcome Measures: Injury incidences of each player were recorded according to the Orchard Sports Injury Classification System (version 10.0) convention to determine the injury classification, location, and type. Results: The incidence of injuries decreased from 15 injuries in the CPP preseason (0.63 [0.77] injuries per player) to 6 injuries in the second preseason when the IRTPP was applied (0.25 [0.53] injuries per player). The days of absence due to injuries also decreased from the CPP preseason (156 d, 10.4 [11.0] d per injury) to the IRTPP preseason (14 d, 2.3 [2.8] d per injury). The injury severity also decreased from the first preseason to the second preseason, and fewer musculoskeletal injuries in the thigh, hip, and groin were reported. Conclusions: The implementation of an IRTPP can reduce the presence of injuries by identifying players potentially at risk and as a result, reducing the injury severity and days lost as a consequence.

Effects of a 10 vs. 20-Min Injury Prevention Program on Neuromuscular and Functional Performance in Adolescent Football Players

Background

Regular injury prevention training is not only effective in reducing sports injury rates, but also in improving neuromuscular and performance-related variables. However, it is currently unknown if this effect can be modified by varying the training dosage.

Objective

To compare the effects of two injury prevention programmes with a different training duration on neuromuscular control and functional performance in adolescent football players.

Methods

342 (15.4 ± 1.7 years) male football players from 18 teams were initially included. The teams were cluster-randomized into two intervention groups. Both groups performed an injury prevention program twice a week during one football season (10 months) using the same exercises but a different duration. One intervention group (INT10, n = 175) performed the program for 10 min, while the other intervention group (INT20, n = 167) for 20 min. At the beginning and end of the season, balance control (Balance Error Scoring System = BESS), jump performance (Squat Jump, Countermovement Jump) and flexibility (Sit and Reach Test, ankle flexibility, hip flexibility) tests were performed. For the final analysis, nine teams with 104 players were considered.

Results

Significant group by time interactions were found for the sit and reach test (p < 0.001) and ankle flexibility (p < 0.001) with higher improvements in the INT20 group. Improvements over the period of one season but no group differences were found for the BESS, Squat Jump and hip flexibility.

Conclusion

Within a single training session, performing structured neuromuscular training with a longer duration is more effective than a shorter duration for improving lower extremity flexibility.

Can musculoskeletal screening test findings guide interventions for injury prevention and return from injury in field hockey?

OBJECTIVES

The aim of this study is to identify if intrinsic factors tested in the preseason screening (PSS) can identify an elevated risk of injury. This aim has two aspects; to assess whether previous injury is associated with ongoing deficits in performance, and to assess if the PSS can identify differences in intrinsic factors that profile risk of future injury.

DESIGN

A cohort of state level field hockey players were tested on a screening test battery including proprioception, postural stability, muscular strength and range of motion, to establish if these intrinsic factors were useful in identifying elevated risk of injury. Retrospective injury data was collated to determine association with previous injury and prospective injury data was collated to determine association with future injury.

PARTICIPANTS

A total of 130 field hockey players were included in this study, from state level squads (age ± SD = 20.96 (3.75); height = 176.09 cm). Groups for prescreening and post screening injury status (injured/not injured) were established for comparison to screening test results.

RESULTS

Right Active Movement Extent Discrimination Assessment (AMEDA), left AMEDA and right Y-balance test (YBT) anterior direction (Ant) were significantly associated (p < 0.05) with injury prior to screening. Right YBTAnt and right and left hip internal rotation (IR) were significantly associated (p < 0.05) with injury post screening. The YBTAnt and YBT posteromedial (PMed) reach directions and Hip IR are associated with previous hamstring injury and show a difference between post screening injured and non-injured groups.

CONCLUSIONS

AMEDA, R YBTAnt, Hip IR tests should be a focus for recovery after previous injury and during season preparation. Full recovery may improve readiness to return to play and reduce risk of primary injury or re-injury. YBTAnt and YBTPmed and Hip IR show a performance deficit link between previous injury and subsequent re-injury of hamstrings. Since these are the most common re-injury types in this cohort, these tests are clinically useful in informing return to play decisions for hockey players.

The relationship between physical fitness attributes and sports injury in female, team ball sport players: a systematic review

BACKGROUND

Understanding the relationships between physical fitness characteristics and sports injury may assist with the development of injury minimisation programs. The purpose of this systematic review was to investigate the association between physical fitness attributes and sports injury in female, team ball sport players.

METHODS

Four scientific databases (MEDLINE, EMBASE, SPORTDiscus, Scopus) and reference lists of relevant research were searched for eligible studies up to September 2, 2019. Full-text articles examining the relationship between physical fitness and sports injury in female, team ball sport players were included. A modified Downs and Black checklist was used to assess methodological quality. Data synthesis determined summary conclusions based on the number of significant relationships divided by the total relationships investigated and reported as a percentage. Level of certainty was identified for summary conclusions based on level of evidence. Sub-analyses regarding competition level, age, and single injury types were also conducted.

RESULTS

A total of 44 studies were included. Data synthesis revealed no associations (low to moderate certainty) between body composition (1/9; 11%), flexibility (18-20%), and balance (2/8; 25%) and 'any injury' classification. No associations (mostly of moderate certainty) were found between flexibility (0-27%), muscular strength (0-27%), and body composition (14-33%) and various body region injury classifications, whereas mixed summary conclusions were shown for balance (0-48%). Many associations between physical fitness and sports injury were deemed 'unknown' or with an insufficient level of certainty. Sub-analyses revealed no association between strength and noncontact ACL injuries (0/5; 0%) or ankle sprains (0/12; 0%), and between flexibility and ankle sprains (1/5; 20%); however, insufficient certainty of these results exists. Clear associations were concluded between balance and lower body injuries in female, non-elite (10/16; 63%) and junior (9/12; 75%) team ball sport players, with moderate and insufficient certainty of these results, respectively.

CONCLUSION

Limited evidence is available to demonstrate relationships between physical fitness and sports injury in female, team ball sport players. High-quality evidence investigating the multifactorial nature of sports injury, including the interactions physical fitness qualities have with other injury determinants, is needed to better understand the role of physical fitness in minimising sports injuries in female, team ball sport players.

TRIAL REGISTRATION

CRD42017077374 (PROSPERO on September 14, 2017).

Assessing thigh muscle balance of male athletes with special emphasis on eccentric hamstring strength

Background: Hamstring strength is important to prevent thigh muscle and knee injuries. Different antagonist-agonist relationships of thigh muscle strength are applied to estimate the injury risk e.g. the intersection point of eccentric hamstring (Hecc) and concentric quadriceps (Qcon) moment-knee flexion angle curves (dynamic control ratio at the equilibrium point = DCRe) and the dynamic control ratio (DCR = Hecc:Qcon). Objective: The aim was to quantify the relationships between DCR, DCRe moments and angles as well as their correlations with peak moments and contractional work of eccentric hamstring and concentric quadriceps exercise. Methods: This cross-sectional study included data from 238 healthy male participants of different sports. They conducted unilateral isokinetic tests obtained at 30°/s and 150°/s for the hamstrings (prone) and the quadriceps (supine). Results: Correlations between DCR and DCRe moments were significant, but weak to moderate in strength (R²_30°/s = 20%, R²_150°/s = 26%). In contrast to DCR (25% ≤ R² ≤ 46%), DCRe moments (80% ≤ R² ≤ 86%) showed very strong relations with peak moments and contractional work of eccentric hamstring exercise. Discussion: DCR and DCRe assess thigh balance by using the same isokinetic raw data. However, weak relations became apparent. DCRe moments were stronger related to eccentric hamstring strength and work than DCR. Therefore, the DCRe moment may serve as meaningful measure of thigh muscle balance because increased eccentric hamstring strength promotes dynamic joint stability and minimizes injury risk.

Injuries and functional performance status in young elite football players: a prospective 2-year monitoring

BACKGROUND

Motor function, such as strength asymmetries of the lower extremities and impaired dynamic stability, have a predictive value for the risk of injury. The present study aimed to reveal potential associations between injury and motor performance.

METHODS

Two hundred and five male youth elite (association) football (soccer) players (mean: 13.5±4.5 years, 57.2±30.2 kg, 168±35 cm) were included. A test battery was conducted twice per season, over two consecutive seasons (four times). Mobility (Sit and Reach Test, SnR), dynamic stability (Single Leg Hop for Distance, SLHD), linear sprinting speed (10 m, 30 m [s]), agility (Zig-Zag test with and without dribbling a ball [s]), jump performance (countermovement jump (CMJ) and drop jump (DJ), in cm) and maximal isometric voluntary force (MIVF, in N) of the knee extensors and flexors were assessed. All injuries occurring over the two-year period, as well as training and competition exposure time, were collected and used as grouping variables for statistical difference testing.

RESULTS

One hundred and twenty-five injuries in 93 players occurred (an injury incidence of 2.7/1000 hours of exposure). Age was associated with injury incidence (r=0.191; P=0.006). Neither DJ, CMJ, SnR nor agility performance were statistically different between injured and non-injured participants (P>0.05). Group differences did occur for sprint and strength (P=0.011; P=0.016), but these lapsed after the inclusion of age as a covariate. Only for SLHD symmetry was a non-significant trend evident after the correction for age (P=0.08).

CONCLUSIONS

The occurrence of musculoskeletal injuries in junior football players are, probably, not related to baseline motor function. Group differences between injured and non-injured youth elite football players are mostly explained by age. Only the symmetry in SLHD could be a potential risk factor for injuries and merits further investigation.

Clinical implications of Landing Error Scoring System calculation methods

OBJECTIVES

To explore whether final Landing Error Scoring System (LESS) scores differ between calculation methods used in literature.

DESIGN

Cross-sectional.

SETTING

Laboratory.

PARTICIPANTS

328 individuals.

MAIN OUTCOME MEASURES

LESS scores from 984 drop-jumps were extracted. Final LESS scores were calculated for every participant according to five methods: mean of 3 jumps, 1st jump score, 3rd jump score, best jump score, and sum of errors present in at least 2 jumps. The influence of the calculation method on group mean LESS score and group-level risk categorization using threshold of 5 errors was estimated using Generalized Estimating Equations, with the mean of 3 jumps score set as the reference method. The agreement in individual-level risk categorization was assessed using odds ratios and McNemar's tests.

RESULTS

Compared to the reference, estimated group mean LESS score was 0.92 errors lower (p < 0.001) using the best jump method, as was group-level risk categorization (odds ratio: 0.50, p < 0.001). Individual-level risk categorization between calculation methods was inconsistent for 8-15% of participants compared to the reference method, significantly different from reference for the best jump score method (p < 0.001).

CONCLUSIONS

Calculation method meaningfully influences final LESS scores and risk categorization.

There Is No Relationship Between Lower Extremity Alignment During Unilateral and Bilateral Drop Jumps and the Risk of Knee or Ankle Injury: A Prospective Study

OBJECTIVE

To investigate the association between lower extremity alignment during unilateral and bilateral drop jump tests and the risk of acute noncontact knee or ankle injuries in young team sport athletes.

DESIGN

Prospective cohort study.

METHODS

A 2-dimensional video analysis was used to measure the frontal plane knee projection angle in the single-leg vertical drop jump (VDJ) and the bilateral VDJ in young team sport athletes. Out of the 364 athletes (187 male, 177 female), 189 played basketball and 175 played floorball.

RESULTS

Six male athletes sustained knee injuries and 23 sustained ankle injuries. Frontal plane knee projection angle in the single-leg VDJ or the bilateral VDJ was not associated with ankle injuries among male athletes. No statistical analysis was performed for the knee injuries. Among female athletes, 28 sustained knee and 41 sustained ankle injuries. Frontal plane knee projection angle during the single-leg VDJ or the bilateral VDJ was not a risk factor for knee or ankle injuries.

CONCLUSION

Lower extremity alignment during unilateral and bilateral drop jump tests was not associated with future noncontact knee or ankle injuries among young team sport athletes. The findings should be interpreted cautiously due to the small number of injuries. J Orthop Sports Phys Ther 2020;50(5):267-274. doi:10.2519/jospt.2020.9247.

Development of a return to play checklist following patellar instability surgery: a Delphi-based consensus

PURPOSE

To date, there is no consensus for the appropriate timing or functional evaluation for safe return to play following patellar instability surgery. The purpose of this study is to develop a consensus-based return to play checklist following patellar stabilization surgery using the Delphi method.

METHODS

A 3-part survey series was conducted following the systematic guidelines of the Delphi technique for gathering consensus from experts in the management of patellofemoral instability. All surveys were completed between July and November of 2017. A literature search was performed in SCOPUS and PubMed to identify existing sources on return to play following patellar instability surgery and determining patellofemoral joint strength in athletes, which served as the basis for the surveys.

RESULTS

12 of the 19 selected participants (63%) completed the first-round survey, 11 of those 12 participants (92%) completed the second-round survey, and 10 of these 11 participants (91%) completed the final survey. Of the final ten participants, there was representation from seven different states in the USA. Nine of the ten (90%) respondents endorsed the final checklist. The final checklist included eight overarching domains with defined and reproducible objective criteria.

CONCLUSION

The standardized list of objective and reproducible criteria for rehabilitation outlined below should help practitioners focus more on patient-centred factors and less on arbitrary timelines. No prior study has gathered consensus from experts on this topic; therefore, this study should serve as a benchmark to help guide patients back to sport safely.

LEVEL OF EVIDENCE

V.

Measures of PHV and the effect on directional dynamic stability to identify risk factors for injury in elite football

BACKGROUND

The aim of this study is to analyze the relationship between peak height velocity (PHV) and dynamic balance (Y-Balance) versus non-peak growth to identify risk factors for non-contact lower limb injuries using a retrospective study design in elite youth footballers.

METHODS

Ninety-three elite category 1 academy football players completed Y-Balance assessment during the preseason screening assessment. Data in relation to Y-Balance and Peak Height Velocity measures was than analyzed retrospectively and correlated against injury audit data to identify relationships between the variables.

RESULTS

A significant correlation was identified between PHV and measures of directional dynamic stability utilizing Y-Balance assessment (P≤0.001). No significant correlations were identified between PHV and injury or injury and dynamic stability scores (P>0.05). Injury occurrence for players within predicted periods of PHV was represented as 45%, within the cohort contained within the study.

CONCLUSIONS

Evidently periods of growth and maturation within elite academy footballers has a detrimental effect on directional dynamic stability performance. However, caution must be taken with interpreting the significance of this relationship and the effect it has on injury occurrence. Consideration must be given to quantifying key etiological factors associated with injury during adolescence and refrain from reliance on measures of PHV.